Sample processing apparatuses which perform processes such as measuring and analyzing sample such as blood and urine are provided with an aspirating unit to aspirate the sample from a container. A predetermined amount of the sample aspirated from one end of the aspirating unit is mixed with reagent such as diluting liquid, drug or the like for processing. Thereafter, the aspirating unit is washed with a washing liquid.
Methods of collecting and quantifying a predetermined amount of aspirated sample include types wherein a predetermined amount of sample is aspirated from one end of an aspirating unit and dispensed into a chamber (for example, Japanese Laid-Open Patent Application No. 1111-272324), and types wherein sample is quantified and collected by a sampling valve provided in the aspirating unit and flows to a chamber together with reagent (for example, Japanese Laid-Open Patent Application No. S59-65769).
When sample is collected via these methods, there is a possibility of adverse effect in the processing results when sample is not properly aspirated by the aspirating unit. To prevent such a problem, a sensor is provided in the aspirating unit to monitor the status of the aspiration performed by the aspirating unit. For example, in the apparatus disclosed in Japanese Laid-Open Patent Application No. H08-015273, an optical detect device is provided in the middle part of the sample flow path to detect clogging of the sample needle by detecting the length of the air column aspirated in the sample flow path via the optical detecting device.
The method disclosed in Japanese Laid-Open Patent Application No. H08-015273 specifically detects an error in the aspiration operation due to clogging of the sample needle and cannot handle the detection of other errors in the aspiration operation.